I've been working on this palette for a game I'm making. It's a shmup with a rainbow powerup mechanic so it needed distinguishable ramps in every hue including making sure indigo can stand apart from blue or and violet, etc.
I started by stealing a handful of key colors I'm fond of from the MSX palette and a couple of colors that are based on the PlayChoice 10 NES palette, then I built out from there over the course of early work so far on the game.
72 colors. I'm pretty new at this but I like where it's at so far.